Refinance smartly investment property

[Mal K.]

Currently we have multiple investment properties financed with a local bank using commercial loans. We also have a 3 unit property we are trying to cash refinance. We are looking to get 30 years mortgage with a fix interest rate. My question is what is the best way to go about it. I have a prime residence through a larger national bank. My partner doesn't have any mortgages under his name accept commercial loans that we have with a local smaller bank for several investment properties. What are our options? Two of the units are currently rented and the last one is still vacant. What would happen if he applies for conventional or FHA loan and says that's his prime residence? Any thoughts. Thanks.